172 THE VOYAGE OF H.M.S. CHALLENGER. 



In Eudyptes chrysolophus (PI. XIV. fig. 1) the tongue measures 2 inches in length 

 and ^vd of an inch in greatest breadth. It resembles in form that of Eudyptes chrysocome, 

 but differs in respect of the number of papillae with which its surface is covered. The 

 papUlse at the tip of the tongue are arranged in three rows, between which, when traced 

 backwards, others are gradually interpolated, so that close to the base of the tongue there 

 are observable no fewer than eight distinct lines of longitudinally arranged papillae. As 

 in Eudyptes chrysocome, they are recurved, and increase in size from the apex to the base 

 of the tongue. The laryngeal pads together measure 1 inch in length and \ an inch 

 in greatest breadth. The papillaj covering them are of small size. They are arranged in 

 three irregular rows on either side of the laryngeal aperture, but become irregularly 

 arranged, and of smaller size towards the external and posterior margins of the pads. 



The buccal group of papUlEe is of relatively larger size than in Eudyptes chrysocome. 

 The papillae composing it are also stouter than in that species. 



The palate of Eudyjotes chrysolophus (PL XIV. fig. 2), immediately behind the smooth 

 quadrilateral plate which fills up the angle of the jaw, presents three rows of papillae on 

 either side of the middle line. The rows, as such, are traceable as far back as the gape, 

 opposite which their number is increased to six. Behind the gape the papUlEe again 

 decrease in number as well as in size, and disappear entirely opposite the articulation of 

 the lower jaw bone. 



The floor of the mouth and the salivary follicles of Eudyptes chrysolophus resemble 

 those of Eudyptes chrysocome. 



In every species of Spheniscus which I have examined, the tongue differs from that 

 of Eudyptes, inasmuch as it is of relatively smaller size. This difference in size of the 

 tongue is most observable when the length of the organ is compared with that of the 

 lower jaw (compare figs. 1 and 3, PI. XIV.). In Eudyptes the tongue extends forwards 

 almost to the symphysis of the lower jaw, whereas in every species of Spheniscus the free 

 extremity of the tongue fails to reach that point. Accordingly in Spheniscus, the tongue 

 instead of covering the entire floor of the mouth, as in Eudyp>tes, leaves a considerable 

 portion of it (about an inch in Spheniscus deinersus) exposed to view. The tongue of 

 Spheniscus, moreover, diflfers from that of Eudyptes in respect of its form. In the former 

 the tongvie is of an elongated triangular form, and diminishes in breadth from base to 

 apex, while in the latter the organ is of nearly uniform Ijreadth throughout. Lastly, in 

 Spheniscus the oral papillae are of considerably smaller size than in Eudyptes, and in 

 every species of Spheniscus the buccal group of papillae is of smaller size than in any 

 species of Eudyptes. 



In Spheniscus demersus (PI. XIV. fig. 5) the tongue measures If inches in length 

 and f ths of an inch in breadth at the base. The lingual papillae are arranged in five rows. 

 One of these occupies the middle line of the tongue, and the others are placed two on 

 either side of it. As in Eudyptes, the papillae of the central row are the largest. The 



